USB drives, like any other portable storage device, are commonplace and a practical way to interchange files between computers. However, a portable USB storage device can host viruses and malware, and the way common operating systems manage the USB drive may allow the malware to infect the computers.
Today many organizations forbid the use of USB drives or even remove or block the USB port from the computers. Other solutions offer an independent computer using an air gap philosophy for reading USBs. These approaches may not be practical (does not solve the problem of moving big files), or secure enough (depends on the end users following policies and norms).